Troubleshooting Mac Mail Issues

Introduction

I ran into a problem where Mac Mail would crash upon opening. This was on El Capitan, but probably applies to all new versions of OS X

Steps
(3 total)

1

Turn off WiFi and disconnect from the Internet

When mail starts, it'll attempt to download or send email. Turn off WiFi or disconnect from the Internet before you launch Mail. In my case there was an outgoing email that was causing Mail to crash. Turning off the internet allowed me to launch mail and delete the email from my outbox. Then I was able to connect to the Internet and resume normal operation.

2

Delete Mail Save State

Mail keeps track of it's last save state in this folder: ~/Library/Containers/com.apple.mail/Data/Library/Save Application State/ com.apple.mail.savedState

Delete this file and open Mail

3

Temporarily Disable Internet Accounts

You can go to System Preferences, and disable your mail accounts at the Operating system level. If the problem is on the account level this will allow you to open Mail.

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